Abstract: Horizontal well multi-stage segmental fracturing is the effective method for the development of the tight gas reservoir in Dingbei gas field in the north of Ordos.Due to deep burial of the reservoir and poor physical property, sand plug or overpressure phenomena continuously appear in the process of earlier fracturing operation in He 1 gas reservoir in Dingbei Block with low operation success ratio.In order to clarify the reason for the difficulties to add sand in the earlier stage and optimize the fracturing design, the researches on proppant flow conductivity evaluation experiment, physical experiment of the proppant passing ability in the fracture and numerical simulation of sand carrier migration rules and etc.have been developed.The experimental results show that the factors of many fractures in the reservoir, dynamic fracture width and mismatch of the proppant sizes are the main reasons for the difficulties of adding sand in the fracturing operation.Therefore, the proppant system, operational discharge capacity and sand ratio of He 1 reservoir in Dingbei block are optimized, and the field application of 6 wells and 45 well sections show that the operational success ratio reaches 97.8%.Thus, the difficult problem of adding sand in horizontal well fracturing in He 1 reservoir of Dingbei Block has been solved and the fracturing effect has been improved, which provide the technical reference to horizontal well fracturing technology for the relative tight gas reservoir.